3.3: The Perfect Paragraph

As Michael Harvey writes, paragraphs are “in essence—a form of punctuation, and like other forms of punctuation they are meant to make written material easy to read.”^[1]   Effective paragraphs are the fundamental units of academic writing; consequently, the thoughtful, multifaceted arguments that your professors expect depend on them. Without good paragraphs, you simply cannot clearly convey sequential points and their relationships to one another. 

Many novice writers tend to make a sharp distinction between content and style, thinking that a paper can be strong in one and weak in the other, but focusing on organization shows how content and style converge in deliberative academic writing. Your professors will view even the most elegant prose as rambling and tedious if there isn’t a careful, coherent argument to give the text meaning. Paragraphs are the “stuff ” of academic writing and, thus, worth our attention here.

Key Sentences (a.k.a. Topic Sentences)

Key Sentences in Academic Writing

In academic writing, each paragraph should have one or two sentences that show its main point. These are often called “topic sentences,” but some instructors prefer “key sentences.” The term “topic sentence” can be confusing. It suggests the sentence only names the topic and must be just one sentence. “Key sentence” is a better term because it expresses the paragraph's central idea. Sometimes, a question or two sentences together can be a key sentence.

Purpose of Key Sentences

Key sentences do two important jobs. First, they state the main idea that the rest of the paragraph supports. Second, they show how each paragraph fits into the argument, often by connecting to the previous paragraph.

Example:

• Version A: Now we turn to the benefits of a college degree.

• Version B: The benefits of earning a college degree include greater job opportunities, increased earning potential, and personal growth.

Both examples mention college degree benefits, but Version B is clearer. It connects the paragraph to earlier ideas and builds the argument, making the logic easy to follow.

Placement of Key Sentences

Academic writing usually puts key sentences at the beginning of each paragraph. This helps readers quickly understand the writer’s argument. When reading, check the first sentence in each paragraph for the main idea. In essays, starting paragraphs with key sentences helps professors see students’ main ideas first and follow the supporting evidence.

Using Key Sentences for Reading and Writing

Key sentences make both reading and writing easier. When reading, look at the first sentence or two of each paragraph for main ideas; then read the details to understand how they fit together. When writing, begin paragraphs with a key sentence to keep ideas clear and the argument strong.

Cohesion and Coherence

After writing a key sentence, the rest of the paragraph should be cohesive and coherent. Cohesion means sentences flow smoothly, linking one idea to the next. Coherence means all sentences are connected and support the main idea of the paragraph. Writing should focus on strong ideas first, then revise for smooth organization and clear language.

Cohesion

Cohesion is the way sentences move from one idea to another. It helps paragraphs flow and makes reading easier. Compare these examples:

Version A:
A college degree is important. People with degrees get better jobs. Earning more money is easier with a degree. Studying in college teaches important skills. Education brings new opportunities.

Version B:
A college degree is important. One reason is that graduates have access to better jobs. These jobs usually offer higher pay. College study also helps students develop important skills, such as communication and problem-solving. Because education brings new opportunities, earning a degree can improve a person's future.

Version B flows better because each sentence begins with familiar information and adds something new, creating a smooth connection from one idea to the next.

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Cohesion makes paragraphs easier to read by connecting sentences; coherence keeps all sentences focused on the main idea.

The first sentence gives the main idea. Each following sentence should start with a familiar idea before adding something new. For example, in a well-written paragraph about college degrees, the first sentence introduces the central idea. The next sentence continues this topic and brings in a new detail. Each sentence links with the previous one. If sentences jump between topics, readers may find the text hard to follow, even if each idea fits the overall subject. The topic stays clear, but poor connections between sentences make reading harder.

If writing feels awkward or choppy, rewrite sentences to start with familiar concepts. If there are several points that don’t connect naturally, numbering them can help. For example: “Advocates of college degrees point to three main benefits.” This lets readers know how each idea fits together.

 

Coherence

Cohesion is about smooth flow between sentences. Coherence is about all sentences fitting together to support the main idea. Sometimes, a paragraph can connect ideas from sentence to sentence but still not be clear on what the main idea is.

For example:
Having a college degree helps shape job choices and future opportunities. Skills learned in college can lead to better decisions. Higher education often leads to stronger problem-solving abilities. These skills can be useful in many areas of life.

All sentences connect, but if they do not relate clearly to one main point, the paragraph loses coherence. Both cohesion and coherence are needed for strong, clear writing.

Building Coherence in Paragraphs

A paragraph works best when each sentence starts with a familiar idea and adds something new. However, strong writing is not just about flow—it also needs to be about one main idea. Free-writing or first drafts may jump from topic to topic. Writers can use these drafts to find the main purpose, then organize the paragraph around that key idea. When the purpose is clear, writing becomes much easier. Coherent paragraphs show that the analysis is thoughtful and well planned.

Concluding Sentences

Some guides say to end each paragraph with a clear conclusion, like a small summary. Most good academic writing does not use this style. The final sentence should be in the writer’s own words, but it does not always need to wrap up the paragraph as if it were an essay. As long as the paragraph supports the key sentence and develops the point, the last sentence can be simple and direct.

Example 1:
The first and last sentence both discuss “little science,” making the paragraph feel complete.

Example 2:
The last sentence introduces a new idea, but the paragraph still works well because all sentences help explain the key idea.

Every sentence in a paragraph should add something new. Do not focus too much on writing a concluding sentence for every paragraph. Instead, make sure each point is explained clearly.

Paragraphs as Structure

Think of paragraphs as punctuation marks that organize writing and make it easier to read. Each paragraph should fit into the flow of ideas. Paragraphs are more like building blocks in a strong structure, each playing an important role in supporting the whole text. Make sure every part has its place and helps develop the overall argument.

 

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1. Michael Harvey, The Nuts and Bolts of College Writing, Second Edition (Indianapolis, IN: Hackett Publishing, 2013), 70. ↵
2. Etiology is the cause of a disease—what’s actually happening in cells and tissues—while epidemiology is the incidence of a disease in a population. ↵
3. Joseph M. Williams.and Joseph Bizup. Style: Lessons in Clarity and Grace 11th edition (New York: Longman, 2014), 68.
 Joseph M. Williams and Joseph Bizup. Style: Lessons in Clarity and Grace 11th edition (New York: Longman, 2014), 68.
 ↵
4. Ibid., 71. ↵
5. The quote uses a version of an ASA-style in-text citation for Mark S. Granovetter, “The Strength of Weak Ties,” American Journal of Sociology 78 (1973): 1360-80. ↵
6. Guiffre. Communities and Networks, 98. ↵
7. Harry Collins and Trevor Pinch, The Golem: What You Should Know About Science 2nd ed. (Cambridge: Canto, 1998), 58. ↵
8. Ibid., 74. ↵